As a packaging material for foods and the like having a yearly-based long shelf life, can has been used. In the case where foods and the like are stored by can, the can exhibit a potent effect for various gas-barrier properties against oxygen, water vapor and the like, but has some problems in that, before opened, the contents could not be visually confirmed, that the canned products could not be heated in a microwave oven, that the canned foods are difficult to take out when they are put in serving dishes or the like, and that the used cans could not be piled up for disposal after use and are therefore kept voluminous, that is, the can lacks in disposal aptitude.
Given the situation, application of plastic containers has become investigated also to the above-mentioned packaging containers that are required to have a long shelf life. As one example, a packaging container formed of a multilayer material container prepared by providing a deoxygenating resin layer containing a deoxidant composition incorporated therein around an already-existing gas-barrier container has been developed, wherein the gas-barrier performance of the container is improved and a deoxygenation function is imparted to the container itself.
PTL 1 discloses a deoxygenating packaging container formed by thermoforming a deoxygenating multilayer body that has an outer layer of a gas-barrier layer formed of a gas-barrier resin and an inner layer of an oxygen-permeable layer formed of an oxygen-permeable resin and, between the two, an interlayer of an oxygen-absorbing layer formed of a deoxidant composition-incorporated oxygen-absorbing resin composition, with the inner layer side kept inside the container, wherein the gas-barrier resin is a mixed resin of a polyamide or a polyamide copolymer, in which the content of the amide structure unit formed through polycondensation of metaxylylenediamine and adipic acid is 90 mol % or more, and an amorphous polyamide in a mixing ratio (mass %) of 80/20 to 30/70.